Problem: Simplify the following expression: $t = \dfrac{5r}{3} \div \dfrac{2r}{9}$
Explanation: Dividing by an expression is the same as multiplying by its inverse. $t = \dfrac{5r}{3} \times \dfrac{9}{2r}$ When multiplying fractions, we multiply the numerators and the denominators. $t = \dfrac{ 5r \times 9 } { 3 \times 2r}$ $t = \dfrac{45r}{6r}$ Simplify: $t = \dfrac{15}{2}$